Index: src/natools-s_expressions-printers-pretty.adb
==================================================================
--- src/natools-s_expressions-printers-pretty.adb
+++ src/natools-s_expressions-printers-pretty.adb
@@ -395,11 +395,11 @@
            and then Width > 0
            and then Cursor > 1
            and then (New_Cursor > Width + 1
              or else (New_Cursor = Width + 1
                and then I + 1 in Data'Range
-               and then not Is_Newline (Data, I, Newline)))
+               and then not Is_Newline (Data, I + 1, Newline)))
          then
             case Newline is
                when CR | LF =>
                   Size := Size + 2;
                when CR_LF | LF_CR =>